Finally biologists can sigh with relief for finding the reason as to why scorpions evolved to glow bright green under ultraviolet light.
Biologist Douglas Gaffin of the University of Oklahoma investigated the 'fluorescence' and found that the creatures can 'sense' light using their tails.
He says the creatures may have evolved the ability to help them scuttle away under rocks, the Daily Mail.
"Scorpions are largely solitary, nocturnal arachnids that glow a bright cyan-green under UV light," wrote Gaffin in a paper in Animal Behaviour.
"The function of this fluorescence is a mystery," he stated.
Gaffin's team 'blindfolded' scorpions, then tested them with various different colours of light and found that the tails seemed to function like secondary 'eyes'.
The insects' shell works as a 'whole-body' sensor, which relays information about light to the nervous system, so any part of a scorpion can 'see'.
The creature's whole body appears to work like a giant 'eye' enabling them to seek shelter more effectively.
"The cuticle (casing) may function as a whole-body light collector which relays information to the nervous system," the researchers wrote.
"Scorpions may use this information to detect shelter, as blocking any part of the cuticle could diminish the signal," they added.